The present disclosure generally relates to water treatment. More particularly, the present disclosure relates to compositions and methods for removal of contaminants from aqueous streams.
Wastewater and natural waters (e.g., surface water or groundwater) may contain a variety of dissolved inorganic substances from natural and anthropogenic sources. Regulatory limits have been set for a number of these substances in drinking water and for discharges to natural waters, for protection of public health and of environmental quality. In many locations, the regulatory limits for many of these substances are set at very low levels, e.g., about 2 to about 50 micrograms per liter (μg/L).
Current water treatment processes, such as granular iron media adsorption, modified coagulation/filtration, reverse osmosis hyperfiltration, anion exchange, activated alumina adsorption, modified lime softening, electrodialysis reversal, and oxidation/filtration, are available and cost-effective for large municipal water treatment facilities. However, as the regulated levels of these contaminants are reduced even further, many of these processes are rendered inadequate. Furthermore, improvements on these technologies or creation of new technologies are needed for small water treatment systems (e.g., those that serve communities of 25 to 10,000 people) and point-of-use or point-of-entry systems (e.g., those for use in private wells) to treat water cost-effectively.
There accordingly remains a need in the art for improved compositions and methods for removing contaminants from aqueous streams.